Gamble Tony
Department of Biological Sciences, Marquette University, Milwaukee, WI, 53201, USA.
Mol Ecol. 2016 May;25(10):2114-6. doi: 10.1111/mec.13648.
Next-generation sequencing methods have initiated a revolution in molecular ecology and evolution (Tautz et al. ). Among the most impressive of these sequencing innovations is restriction site-associated DNA sequencing or RAD-seq (Baird et al. ; Andrews et al. ). RAD-seq uses the Illumina sequencing platform to sequence fragments of DNA cut by a specific restriction enzyme and can generate tens of thousands of molecular genetic markers for analysis. One of the many uses of RAD-seq data has been to identify sex-specific genetic markers, markers found in one sex but not the other (Baxter et al. ; Gamble & Zarkower ). Sex-specific markers are a powerful tool for biologists. At their most basic, they can be used to identify the sex of an individual via PCR. This is useful in cases where a species lacks obvious sexual dimorphism at some or all life history stages. For example, such tests have been important for studying sex differences in life history (Sheldon ; Mossman & Waser ), the management and breeding of endangered species (Taberlet et al. ; Griffiths & Tiwari ; Robertson et al. ) and sexing embryonic material (Hacker et al. ; Smith et al. ). Furthermore, sex-specific markers allow recognition of the sex chromosome system in cases where standard cytogenetic methods fail (Charlesworth & Mank ; Gamble & Zarkower ). Thus, species with male-specific markers have male heterogamety (XY) while species with female-specific markers have female heterogamety (ZW). In this issue, Fowler & Buonaccorsi () illustrate the ease by which RAD-seq data can generate sex-specific genetic markers in rockfish (Sebastes). Moreover, by examining RAD-seq data from two closely related rockfish species, Sebastes chrysomelas and Sebastes carnatus (Fig. ), Fowler & Buonaccorsi () uncover shared sex-specific markers and a conserved sex chromosome system.
新一代测序方法引发了分子生态学和进化领域的一场革命（陶茨等人）。这些测序创新中最令人瞩目的是限制性位点关联DNA测序，即RAD-seq（贝尔德等人；安德鲁斯等人）。RAD-seq利用Illumina测序平台对由特定限制性酶切割的DNA片段进行测序，并能生成数以万计的分子遗传标记用于分析。RAD-seq数据的众多用途之一是识别性别特异性遗传标记，即在一个性别中发现而在另一个性别中未发现的标记（巴克斯特等人；甘布尔和扎尔科沃）。性别特异性标记对生物学家来说是一种强大的工具。最基本的是，它们可用于通过聚合酶链反应（PCR）鉴定个体的性别。这在一个物种在某些或所有生活史阶段缺乏明显的两性异形的情况下很有用。例如，此类测试对于研究生活史中的性别差异（谢尔登；莫斯曼和瓦泽）、濒危物种的管理和繁殖（塔贝莱特等人；格里菲思和蒂瓦里；罗伯逊等人）以及胚胎材料的性别鉴定（哈克等人；史密斯等人）都很重要。此外，在标准细胞遗传学方法失败的情况下，性别特异性标记有助于识别性染色体系统（查尔斯沃思和曼克；甘布尔和扎尔科沃）。因此，具有雄性特异性标记的物种具有雄性异配性别（XY），而具有雌性特异性标记的物种具有雌性异配性别（ZW）。在本期中，福勒和布奥纳科尔西（）说明了RAD-seq数据在岩鱼（Sebastes）中生成性别特异性遗传标记的容易程度。此外，通过检查两种亲缘关系密切的岩鱼物种，即红胸岩鱼（Sebastes chrysomelas）和肉色岩鱼（Sebastes carnatus）（图）的RAD-seq数据，福勒和布奥纳科尔西（）发现了共享的性别特异性标记和保守的性染色体系统。
